that kit make us less productive. is the same true when it come to using our down time? why not answer e-mails when we wait in line or watch tv during a workout? scientists who study the brain say not resting your mind could hurt your ability to learn and remember new things. >> reporter: are smart phones actually making us dumb? whether it is this device or that, having access to the world in the palm of our hands. back in the old days -- >> wethove cee re aerivove the listen to the dial tone. >> reporter: we might just be doing nothing. >> i work full time. i try to do some reading and because i like to block out noise, i hear my ipod and watch tv at the same time. >> reporter: for 20 something mike, down time is so 1990s. >> even on weekends when i'm sleeping, in i have my phone and my laptop beside my bed. i have e-mails for work and i study for class and i have phone calls coming. in. >> reporter: credit that to our go-go lifestyle. one in four has a cell phoning, of that a third smart with the mobile sgeb nearly half end their day the same way. in between, you've s